1. Field of the Invention
The present invention relates to a substrate carrier container equipped with an electrically operable component, for temporarily storing or carrying a workpiece, such as a semiconductor substrate, a photomask, or a magnetic disk. More particularly, the present invention relates to an apparatus for and a method of supplying electric power from an external power source to a substrate carrier container, and to an apparatus for and a method of charging a secondary cell in a substrate carrier container.
2. Description of the Related Art
In many cases, highly hermetically sealed containers are used for carrying and storing substrates, such as semiconductor substrates or glass substrates, which are being fabricated in semiconductor fabrication factories. Such a highly hermetically sealed container basically serves to protect the stored substrates from contaminants that are present outside of the containers. Contaminants are also produced from the material of the container and the stored substrates, and attached to the inner surface of the container. Therefore, unless the container is frequently cleaned, the contaminants attached to the inner surface of the container tend to contaminate a clean substrate that is stored in the container and is to be differently processed in a next process. Those highly hermetically sealed containers are usually equipped with no electrical component such as an electronic air cleaner.
As semiconductor devices on semiconductor substrates become smaller in size and different interconnection materials are used on the semiconductor substrates, it is necessary to employ a control device for reducing contaminants other than particulate contaminants, e.g., gaseous contaminants or native oxide formed in the presence of oxygen and water. A combination of a fan motor, a particle removal filter, a gas removal filter, and the like can reduce gaseous contaminants, and a substrate carrier container having such a combination has commercially been available. In another method of reducing gaseous contaminants, particulate contaminants are removed with ultraviolet photoelectrons, and organic substances are decomposed into harmless substances with a photocatalyst. There has been proposed a substrate carrier container having a device that can perform these processes. Further, there has also been commercially available a portable desiccator having a recoverable dehumidifying agent or an electronic dehumidifying unit. Presently available portable containers having such functions for reducing contaminants are usually equipped with a rechargeable secondary cell or are supplied with electric power from an external power source to energize an air cleaner or the like. Since those portable containers have not been designed from the viewpoint of automatic operation in semiconductor fabrication factories, connection terminals for charging the secondary cells or supplying electric power from the external power source are connected and disconnected directly by an operator in many cases.
Generally, a portable device and an industrial device equipped with a secondary cell cannot be operated continuously unless the secondary cell is charged. For example, a small lightweight device having a secondary cell, such as a portable telephone or an electrically operated toothbrush, is directly placed on a charger to charge the secondary cell in the device. Many connectors for connecting the portable device to the charger use a fixed leaf spring because the device is lightweight, the charging current is low, the device is placed directly on the charger by an operator, and the connector has a low requirement for reliability.
An industrial device equipped with a secondary cell tends to be large in size, consume a large current, and have a high requirement for reliability. Therefore, many industrial devices use sockets and plugs for connection to chargers. In the case where a connector in a device equipped with a secondary cell is not connected by an operator, i.e., the connector is connected by a robot or an automatic moving mechanism in an automated factory, for example, a highly reliable connection can be established only when the device has an accurate positioning mechanism and a highly durable connector. Since a medium-sized device or a large-sized device generally has a large space therein for a connector, the dimensions of the accurate positioning mechanism and the connector do not pose significant problems. However, a small-sized device such as a substrate carrier container does not have a large space therein for a connector. Therefore, it is necessary to make efforts to establish a highly reliable connection within a relatively small space.
A substrate carrier container that accommodates twenty-five 8-inch substrates weighs about 5 kg, and a substrate carrier container that accommodates twenty-five 12-inch substrates weighs about 10 kg. In an automated semiconductor fabrication factory, a substrate carrier container is mechanically handled and transported by a transportation machine such as an automated guided vehicle (AGV) or an overhead hoisting transfer (OHT). When the substrate carrier container is transported and seated on a power supply apparatus with the use of such a transportation machine, there is a strong possibility that a connection terminal for connecting the substrate carrier container to the power supply apparatus is damaged due to the shock caused by seating action. Particularly, a spring-type charging connector is prone to be damaged in such an environment.
It is therefore an object of the present invention to provide a power supply apparatus which can highly reliably supply electric power to a substrate carrier container equipped with a rechargeable secondary cell and an air cleaner energized by the secondary cell or a substrate carrier container equipped with an air cleaner energized by an external power source.
According to a first aspect of the present invention, there is provided a power supply apparatus for supplying electric power to a substrate carrier container having a rechargeable cell, comprising: a body for seating a substrate carrier container thereon; a seating detecting device provided on the body for detecting whether the substrate carrier container is seated on the body or not; a power supply connector movably provided on the body; and a control mechanism for bringing the power supply connector into contact with a charging terminal of the substrate carrier container to charge the rechargeable cell in the substrate carrier container according to a detected signal from the seating detecting device.
According to a second aspect of the present invention, there is provided a power supply apparatus for supplying electric power to a substrate carrier container having an electrical component energized by an external power source, comprising: a body for seating a substrate carrier container thereon; a seating detecting device provided on the body for detecting whether the substrate carrier container is seated on the body or not; a power supply connector movably provided on the body; and a control mechanism for bringing the power supply connector into contact with a power supply terminal of the substrate carrier container to supply electric power to the electrical component according to a detected signal from the seating detecting device.
Preferably, the substrate carrier container has at least one of an air cleaner and a dehumidifying device disposed therein. It is desirable that the seating detecting device comprises at least one of a mechanical switch, a proximity switch, and a photoelectric sensor. Preferably, the power supply connector comprises a fitting-type connector or a contact-type connector.
According to a third aspect of the present invention, there is provided a method of supplying electric power to a substrate carrier container having a rechargeable cell, comprising: seating a substrate carrier container on an body of a power supply apparatus; detecting whether the substrate carrier container is seated on the body with a seating detecting device provided on the body or not; moving a power supply connector provided on the body to bring the power supply connector into contact with a charging terminal of the substrate carrier container; charging the rechargeable cell in the substrate carrier container according to a detected signal from the seating detecting device; and returning the power supply connector to an original position thereof after the rechargeable cell is charged.
According to a fourth aspect of the present invention, there is provided a method of supplying electric power to a substrate carrier container having an electrical component energized by an external power source, comprising: seating a substrate carrier container on an body of a power supply apparatus; detecting whether the substrate carrier container is seated on the body with a seating detecting device provided on the body or not; moving a power supply connector provided on the body to bring the power supply connector into contact with a power supply terminal of the substrate carrier container; supplying electric power to the electrical component according to a detected signal from the seating detecting device; and returning the power supply connector to an original position thereof after the electric power is supplied to the electrical component.
With the above arrangement of the present invention, the power supply apparatus comprises the seating detecting device for detecting whether the substrate carrier container is seated in a predetermined position on the power supply apparatus. According to detected information from the seating detecting device, the power supply connector of the power supply apparatus is moved to be brought into contact with the power supply terminal of the substrate carrier container. Thus, the secondary cell is charged, or the electrical component energized by an external power source is supplied with electric power. When the charging of the cell or the supply of electric power to the electrical component is completed, or when the substrate carrier container is moved from the power supply apparatus, the power supply connector is returned to its original position. Therefore, the power supply connector is prevented from being damaged, and a highly reliable connection can be established.
The above and other objects, features, and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings which illustrate a preferred embodiment of the present invention by way of example.